**FILE** M23 rebels withdraw from the Masisi and Sake areas in the eastern Congo town of Sake, some 27 kms west of Goma, on Nov. 30, 2012. (Associated Press)

Police Nationale du Congo officers who fled Goma when M23 rebels took over the city Nov. 18 2012, return on a barge to the port of Goma, eastern Congo, Friday Nov. 30, 2012. The police force were returning to resume control on Friday, as had been agreed by the regional bloc. Rebels in Congo believed to be backed by Rwanda postponed their departure Friday from the key eastern city of Goma by 48 hours for Ã¬logistical reasons,Ã® defying for a second time an ultimatum set by neighboring African countries and backed by Western diplomats. The delay raises the possibility that the M23 rebels donÃ­t intend to leave the city they seized last week, giving credence to a United Nations Group of Experts report which argues that neighboring Rwanda is using the rebels as a proxy to annex territory in mineral-rich eastern Congo.(AP Photo/Jerome Delay)

M23 rebels withdraw from the Masisi and Sake areas in the eastern Congo town of Sake, some 27 kms west of Goma, Friday Nov. 30, 2012. Rebels in Congo believed to be backed by Rwanda postponed their departure Friday from the key eastern city of Goma by 48 hours for Ã¬logistical reasons,Ã® defying for a second time an ultimatum set by neighboring African countries and backed by Western diplomats. The delay raises the possibility that the M23 rebels donÃ­t intend to leave the city they seized last week, giving credence to a United Nations Group of Experts report which argues that neighboring Rwanda is using the rebels as a proxy to annex territory in mineral-rich eastern Congo.(AP Photo/Jerome Delay)

Police Nationale du Congo officers who fled Goma when M23 rebels took over the city Nov. 18, 2012, return on a barge to the port of Goma, eastern Congo, Friday Nov. 30, 2012. The police force were returning to resume control on Friday, as had been agreed by the regional bloc. Rebels in Congo believed to be backed by Rwanda postponed their departure Friday from the key eastern city of Goma by 48 hours for Ã¬logistical reasons,Ã® defying for a second time an ultimatum set by neighboring African countries and backed by Western diplomats. The delay raises the possibility that the M23 rebels donÃ­t intend to leave the city they seized last week, giving credence to a United Nations Group of Experts report which argues that neighboring Rwanda is using the rebels as a proxy to annex territory in mineral-rich eastern Congo.(AP Photo/Jerome Delay)

Children walk past M23 rebels in the eastern Congo town of Sake, some 27 kms west of Goma, Thursday Nov. 29, 2012. Rebels, who last week seized one of the most important cities in eastern Congo and advanced beyond, said Thursday that they had pulled back several miles (kilometers ) to the town of Sake and were on track to leave the key city of Goma by Friday, in accordance with a deadline imposed by the international community.(AP Photo/Jerome Delay)

M23 rebels withdraw from the Masisi and Sake areas in the eastern Congo town of Sake, some 27 kms west of Goma, Friday Nov. 30, 2012. Rebels in Congo believed to be backed by Rwanda postponed their departure Friday from the key eastern city of Goma by 48 hours for Ã¬logistical reasons,Ã® defying for a second time an ultimatum set by neighboring African countries and backed by Western diplomats. The delay raises the possibility that the M23 rebels donÃ­t intend to leave the city they seized last week, giving credence to a United Nations Group of Experts report which argues that neighboring Rwanda is using the rebels as a proxy to annex territory in mineral-rich eastern Congo.(AP Photo/Jerome Delay)

M23 rebels gather in the eastern Congo town of Sake, some 27 kms west of Goma, Thursday Nov. 29, 2012. Rebels, who last week seized one of the most important cities in eastern Congo and advanced beyond, said Thursday that they had pulled back several miles (kilometers ) to the town of Sake and were on track to leave the key city of Goma by Friday, in accordance with a deadline imposed by the international community.(AP Photo/Jerome Delay)

A soldier of the Mai Mai militia rests in Kirotshe, some 30 kms south-west of Goma, Thursday Nov. 29, 2012. M23 Rebels, who last week seized one of the most important cities in eastern Congo and advanced beyond, said Thursday that they had pulled back several miles (kilometers ) to the town of Sake and were on track to leave the key city of Goma by Friday, in accordance with a deadline imposed by the international community. Government troops were massing in Minova.(AP Photo/Jerome Delay)

FARDC Congolese government special forces gather in a stadium near Minova, Congo some 40 kms south-west of Goma, Thursday Nov. 29, 2012, for a moral building gathering and an address by their commander General Bahouma .M23 Rebels, who last week seized one of the most important cities in eastern Congo and advanced beyond, said Thursday that they had pulled back several miles (kilometers ) to the town of Sake and were on track to leave the key city of Goma by Friday, in accordance with a deadline imposed by the international community. Governement troops were massing in Minova.(AP Photo/Jerome Delay)

GOMA, Congo (AP) — Rebels in Congo believed to be backed by Rwanda Friday postponed indefinitely their departure from the key eastern city of Goma, defying for a second time an ultimatum set by neighboring nations.

The delay raises the possibility that the M23 rebels don’t intend to leave the city they seized last week, giving credence to a United Nations Group of Experts report which argues that neighboring Rwanda is using the rebels as a proxy to annex territory in mineral-rich eastern Congo.

An M23 spokesman said Friday morning that for “logistical reasons” the rebels needed 48 more hours to complete their withdrawal, promising that the fighters would leave the city by Sunday.

Later in the day, the rebels attempted to force their way into Goma’s international airport in order to seize arms belonging to the Congolese military which were being safeguarded there. Although the city fell to the rebels last week, United Nations peacekeepers regained control of the airport and on Friday, they blocked the fighters from entering, prompting the rebels to cry foul, and say that this “changes everything.”

“The (U.N.) is blocking us. They are not letting us organize ourselves logistically, and letting us reach our ammunitions at the airport. This could change everything. We will not leave until this is solved. It depends on the (U.N.) now,” said M23 Gen. Sultani Makenga.

The regional bloc representing the nations bordering Congo had issued a Friday deadline for the M23 fighters to retreat, after the rebels had thumbed their nose at an earlier ultimatum. The statements made by the rebels on Friday suggest they are dragging their feet.

“We are not blocking them from leaving Goma, that is absolutely not true,” said Madnodje Mounoubai, the spokesman for the U.N. peacekeeping mission. “They are complaining because they want access to airport, and want access to the arms that belong to the FARDC (the Congolese army) that are stored at the airport. This is something that we will not allow or tolerate.”

In a sign of how confused the situation remained on Friday in Goma, a barge carrying around 280 Congolese policemen arrived at the city’s port on the banks of Lake Kivu. The policemen had fled when the rebels took the city, and were returning to resume control on Friday, as had been agreed in the accord signed by the rebels and regional leaders in Kampala, the capital of neighboring Uganda.

The Kampala accord called for M23 to hold a ceremony officially handing back the city to local authorities. Because the rebels had not yet left Goma, the officers stayed on the boat, as their superiors tried to negotiate with the occupiers.

“We are finishing a meeting to determine what they will do,” said Jean-Marie Musafari, police spokesman in Goma.

By evening, the officers now hungry and bored were still on the barge, waiting for orders. “We can’t spend the night here,” said Capt. Bradoc Aoshi.

The one positive sign was the movement of troops in the two areas that M23 captured after they took Goma. The accord had called for the thousands of fighters to retreat from the furthest point first — Masisi. From there, they would go to Sake, some 27 kilometers (18 miles) west of Goma, before withdrawing completely from Goma to a position 20 kilometers (12 miles) north of the provincial capital.

In Sake, reporters saw a 2-kilometer (1.2-mile) long column of M23 soldiers moving out. The column of soldiers was at least 1,000-deep. They carried their weapons, including mortar launchers on their heads and rocket-propelled grenades on their backs. They walked in an orderly fashion. All in silence. The people of Sake stood to the side watching, not clapping or shouting.

The M23 rebels are widely believed to be supported by Rwanda, which according to the U.N. report, has provided them with battalions of soldiers, arms and financing.

Congo, an enormous, sprawling Central African nation, has twice been at war with its much smaller but more affluent and better organized neighbor.

The eight-month-old M23 rebellion is led by fighters from a now-defunct rebel group, who agreed to lay down their arms on March 23, 2009, in return for being allowed to join the ranks of the Congolese army. M23 takes its name from the date of that accord, and the rebellion began in April, when hundreds of soldiers defected from the military, saying that the terms of the accord had not been respected.

In fact, most analysts believe the origin of the rebellion is a fight over Congo’s vast mineral wealth, a good chunk of which is found in the North Kivu province where Goma is the capital. Starting this spring, the fighters seized a series of small towns and villages in North Kivu, culminating with the capture on Nov. 20 of Goma, a population hub of 1 million and a key, mineral trading post.

On Friday in London, the British government announced that it will not release its next payment of budget support to Rwanda. United Kingdom International Development Secretary Justine Greening said that the 21 million ($33.7 million) of general budget support, which was due in December, is not being disbursed as a result of Rwanda’s role in the conflict in Congo.

“The government has already set out its concerns over credible and compelling reports of Rwandan involvement with M23 in DRC. This evidence constitutes a breach of (our) partnership principles,” he said, “And as a result I have decided not to release the next payment of budget support to Rwanda.”